Improvement in balanced valves



G, MSSP.4

- Balanced-Valves.V

N0, 167,462, I PatentedSept. 7,1875.

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GEORGE MOSSOP, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN BALANCED VALVES.

Specification forming part of Letters Patent No. 167,462, dated September 7, 1875; application filed June 28, 1875.

To all 'whom t may concern:

Be it known that I, GEORGE MOSSOP, of the city of Philadelphia and State of Pennsylvania, have invented Improvements in Slide- Valves for Steam-Engines, of which the following is a speoication:

The invention has for its objection the disburdening a slide-valve of the pressure of steam in the steam-chest.

The accompanying drawing-a vertical diametrical section-fully illustrates the nature and object of the invention.

A represents a slide-valve; B, the face ot' the steam-cylinder; and O, the steam-chest cover. On the back of the valve is a cylinder, D, into which is tted the pistons E F, which are connected by the bolt G, so as to be either rigid or flexible. The piston E, shown partly sectioned, is annular, and has its wall a graduall)Y thinned toward the top, to spring and spread when pressure is applied. The upper piston has a cap or iiange, H, which presses against the inner side of the valve-chest cover C. The steam in the steam-chest enters the cylinder I) through the openings b and the indentations c made in the tiange H. Its pressure on the upper piston F, together with that exerted on the flange H, is slightly in excess of that on the bottom piston E, by which the top or cap H is forced, steam-tight, against the inner side of the valve-chest cover, Without causing excessive friction when the valve is in motion. The pressure of the steam against the thinned wall a ofthe lower piston E springs it, steam-tight, against the surface of the cy1` inder, and thus prevents the steam from escaping into the valve.

Vhen the steam is shut off from the steamchest, the contact of the piston F and the steam-chest cover is reta-ined by a spring, I, which bears between the valve E and the top J ot' the valve A. The water of condensation which may settle in the' bottom of the cylinder D, when the piston E is cooled and contracted, is drained olfv through the openings d in the top of the valve, to the exhaust-openings of the same.

The rod or bolt G which connects the pistons can, as before stated, be rigid or eXible-liexible to permit the piston F to accom- .nlodate itself to any unevenuess of' the steamchcst cover.

The cylinder D and the pistons can be of other forms than cylindrical.

I claim as my inventionl. In a balanced valve, the combinationot` the cylinder D, the pistons E E, and apertures for conducting the steam to the space between the said pistons, substantially as and for the purpose shown and described.

2. The piston E, having a thin tapering shell, a., in combination with the cylinder D, said shell being forced, byI the action of the steam, steam-tight against the piston D, substantially as shown and described.

VIn testimony whereof I hereunto sign my name in presence of two subscribing witnesses.

GEORGE MOSSOP.

Witnesses:

FRANCIS D. PAsToRIUs, PHILIP A. CREGAR. 

